<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        //用户输入数值
        let num1 = +prompt('输入数值1')
        let num2 = +prompt('输入数值2')
        function jh(a,b) {
         let tmpe
         tmpe=a
         a=b
         b=tmpe
         return `${a}${b}`
        }
        let str = jh(num1,num2)
        document.write(str)
    </script>
</body>
</html>